Dolphins
Dolphins are very intelligent and they seem to be well loved by humans. This aquatic mammal has been able to fascinate us in a variety of ways. They are curious, form strong bonds within their pod, and they have been known to help humans in a variety of circumstances including rescues and with fishing. There are 36 different species of dolphins that have been recognized. 32 of them are marine dolphins which are those that we are the most aware of and 4 of them are river dolphins. It can be very interesting to look at each of these species uniquely versus dolphins as a whole. They are very entertaining due to the leaps that they make out of the water. Some of them leap up to 30 feet in the air as they do so. They have to come to the surface to for water at different intervals to get air. This can be from 20 seconds to 30 minutes between when they get air. The body of the dolphin is grayish blue and the skin is very sensitive to human touch and to other elements that could be in the water. Even though dolphins have 100 teeth, they don’t use them for eating. They do use them to get the fish though and then they swallow them. They can consume up to 30 pounds fish per day. They usually work as a team in their pod to get the school of fish surrounded and balled up. From there, they can plow through the middle and eat plenty as they do so. They take turns doing this so that all that participated get to dine on the fish. This is just one of the many different types of feeding strategies that they may take part in. They do what is necessary to get the food for the pod members. It can include jumps, zig zag patterns, circles, and a combination of efforts to get the job done. Most of the species of dolphins live in saltwater but there are some that are able to do well in the freshwater locations. They are mainly found in the freshwater of the Amazon River. They are easily seen by humans as they tend to stick to the swallow locations of the water. It is amazing the difference in size of the various species of dolphins. The larger ones can weigh about 11 tons and be close to 30 feet long. The smaller ones are about 90 pounds and 4 feet long. Between those two spectrums you will find all weights and lengths. The species as well as their location play a huge role in their overall size. The body of a dolphin is designed to help them move through the water quickly and without exerting huge amounts of energy. They rely on their pectoral fins and the fluke (tail) to help them navigate through the water. Human Threats Some dolphin species face an uncertain future, especially some river dolphin species such as the Amazon river dolphin, and the Ganges and Yangtze river dolphin, which are critically or seriously endangered. A 2006 survey found no individuals of the Yangtze river dolphin, which now appears to be functionally extinct. Pesticides, heavy metals, plastics, and other industrial and agricultural pollutants that do not disintegrate rapidly in the environment concentrate in predators such as dolphins. Injuries or deaths due to collisions with boats, especially their propellers, are also common. Various fishing methods, most notably purse seine fishing for tuna and the use of drift and gill nets, unintentionally kill many dolphins. Accidental by-catch in gill nets and incidental captures in antipredator nets that protect marine fish farms are common and pose a risk for mainly local dolphin populations. In some parts of the world, such as Taiji in Japan and the Faroe Islands, dolphins are traditionally considered as food, and are killed in harpoon or drive hunts. Dolphin meat is high in mercury, and may thus pose a health danger to humans when consumed. Dolphin safe labels attempt to reassure consumers fish and other marine products have been caught in a dolphin-friendly way. The earliest campaigns with "Dolphin safe" labels were initiated in the 1980s with collusion between marine activists and the major tuna companies, and involved decreasing incidental dolphin kills by up to 50% by changing the type of nets used to catch tuna. The dolphins are netted only while fishermen are in pursuit of smaller tuna. Albacore are not netted this way, making albacore the only truly dolphin-safe tuna. Loud underwater noises, such as those resulting from naval sonar use, live firing exercises, or certain offshore construction projects, such as wind farms, may be harmful to dolphins, increasing stress, damaging hearing, and causing decompression sickness by forcing them to surface too quickly to escape the noise. Gallery Screenshot 2016-11-20-00-07-24.png Screenshot 2016-11-19-23-44-24.png Screenshot 2016-11-19-23-44-16.png Screenshot 2016-11-19-23-44-13.png Category:Animals Category:Water